Inhibitory effects of polysaccharides isolated from Phellinus gilvus on benzo(a)pyrene-induced forestomach carcinogenesis in mice

Structural diversity and bioactivity of polysaccharides from medicinal mushroom Phellinus spp.: A review

Phellinus spp., an important medicinal fungus mushroom extensively cultivated and consumed in East Asia for over 2000 years, is traditionally considered a precious food supplement and medicinal ingredient. Published studies showed that the polysaccharides are major bioactive macromolecules from Phellinus spp. (PPs) with multiple health-promoting effects, including immunomodulatory, anti-cancer, anti-inflammatory, hepatoprotective, hypoglycemic, hypolipidemic, antioxidant, and other bioactivities. Although the polysaccharides extracted from the fruiting body, mycelium, and fermentation broth of Phellinus spp. have been extensively studied for the extraction and purification methods, structural characteristics, and pharmacological activities, the knowledge for their structures and bioactivity relationship, toxicologic effects, and pharmacokinetic profile is limited. This review systematically summarizes the recent progress in the isolation and purification, chemical structures, bioactivities, and the underlying mechanisms of PPs. Information from this review provides insights into the further development of polysaccharides from PPs as therapeutic agents and functional foods.

Aqueous extracts of Sanghuangporus vaninii induce S-phase arrest and apoptosis in human melanoma A375 cells

Sanghuangporus vaninii, also called 'Sanghuang' mushroom in Chinese, has various medicinal uses, but its effects on human melanoma cells have not been reported. The present study investigated the inhibitory ability and potential anticancer mechanism of the aqueous extracts of S. vaninii (SH). The results revealed that SH inhibited the proliferation of A375 human melanoma cells in a dose-dependent manner, and flow cytometry analysis suggested that SH induced A375 cell cycle arrest at S phase and apoptosis. Reverse transcription-quantitative PCR, western blotting and immunofluorescence analyses indicated that SH induced S-phase arrest by upregulating p21 expression, and p21 inhibited the expression of cyclin-cyclin-dependent kinases complexes at both the RNA and protein levels. In addition, SH induced apoptosis of A375 cells by inhibiting the expression levels of the anti-apoptosis gene Bcl-2. Therefore, the results suggested that SH may be a potential candidate for the treatment of human melanoma, thus providing new ideas for developing drugs that target melanoma.

Advances in antitumor polysaccharides from phellinus sensu lato: Production, isolation, structure, antitumor activity, and mechanisms

Edible and medicinal fungi (mushrooms) are widely applied to functional foods and nutraceutical products because of their proven nutritive and medicinal properties. Phellinus sensu lato is a well-known medicinal mushroom that has long been used in preventing ailments, including gastroenteric dysfunction, diarrhea, hemorrhage, and cancers, in oriental countries, particularly in China, Japan, and Korea. Polysaccharides represent a major class of bioactive molecules in Phellinus s. l., which have notable antitumor, immunomodulatory, and medicinal properties. Polysaccharides that were isolated from fruiting bodies, cultured mycelia, and filtrates of Phellinus s. l. have not only activated different immune responses of the host organism but have also directly suppressed tumor growth and metastasis. Studies suggest that polysaccharides from Phellinus s. l. are promising alternative anticancer agents or synergizers for existing antitumor drugs. This review summarizes the recent development of polysaccharides from Phellinus s. l., including polysaccharide production, extraction and isolation methods, chemical structure, antitumor activities, and mechanisms of action.

Polycyclic aromatic hydrocarbons and digestive tract cancers: a perspective

Cancers of the colon are most common in the Western world. In majority of these cases, there is no familial history and sporadic gene damage seems to play an important role in the development of tumors in the colon. Studies have shown that environmental factors, especially diet, play an important role in susceptibility to gastrointestinal (GI) tract cancers. Consequently, environmental chemicals that contaminate food or diet during preparation become important in the development of GI cancers. Polycyclic aromatic hydrocarbons (PAHs) are one such family of ubiquitous environmental toxicants. These pollutants enter the human body through consumption of contaminated food, drinking water, inhalation of cigarette smoke, automobile exhausts, and contaminated air from occupational settings. Among these pathways, dietary intake of PAHs constitutes a major source of exposure in humans. Although many reviews and books on PAHs and their ability to cause toxicity and breast or lung cancer have been published, aspects on contribution of diet, smoking and other factors toward development of digestive tract cancers, and strategies to assess risk from exposure to PAHs have received much less attention. This review, therefore, focuses on dietary intake of PAHs in humans, animal models, and cell cultures used for GI cancer studies along with epidemiological findings. Bioavailability and biotransformation processes, which influence the disposition of PAHs in body and the underlying causative mechanisms of GI cancers, are also discussed. The existing data gaps and scope for future studies is also emphasized. This information is expected to stimulate research on mechanisms of sporadic GI cancers caused by exposure to environmental carcinogens.

Current advances in Phellinus sensu lato: medicinal species, functions, metabolites and mechanisms

Twenty-six species of Phellinus sensu lato, reported as medicinal mushrooms, are enumerated in this review. The species' names were checked and revised according to contemporary taxonomy and the latest version of the International Code of Botanical Nomenclature (Vienna Code); two misapplied names of Phellinus baumii Pilát and Phellinus himalayensis Y.C. Dai in previous reports are also discussed. Of the 20 types of medicinal functions, the most shared functions are antitumor and improving immunity, both of which may be viewed as the basal functions of Phellinus s. l. In addition, alleviating septic shock, anti-inflammatory, and antioxidation are also a routine functions mentioned often. The main medicinal metabolites, including several kinds of polysaccharides and polyphenols, are introduced. Different methods and conditions could purify various polysaccharides with difference in activity level even from the same species, while all polyphenols are hispidin and its derivatives in general. Three aspects of mechanism contribute to antitumor activities of polysaccharides: (1) promoting an immune response, (2) inducing cell apoptosis, and (3) inhibiting metastasis. Other general mechanisms of the metabolites in antioxidant activity, and in treating diabetes, as well as complications are summarized. We also elaborate on potential scientific strategies for obtaining the medicinal metabolites from Phellinus s. l., such as artificial cultivation, the discoveries of more species with medicinal functions, the utilization of species growing quickly, and the optimization of culture conditions and media supplements in fermentation.

Comparison of intraperitoneal anti-adhesive polysaccharides derived from Phellinus mushrooms in a rat peritonitis model

AIM: To assess the adhesion- and abscess-reducing capacities of various concentrations of polysaccharides derived from fungus, Phellinus gilvus (PG) or Phellinus linteus (PL) in a rat peritonitis model.

METHODS: In 96 SD rats, experimental peritonitis was induced using the cecal ligation and puncture model (CLP). Rats were randomly assigned to 8 groups; Ringer’s lactate solution (RL group), hyaluronic acid (HA group), 0.025%, 0.25%, and 0.5% polysaccharides from PG (PG0.025, 0.25, and 0.5 groups), and PL (PL0.025, 0.25, and 0.5 groups). Adhesions and abscesses were noted at 7 d after CLP. RT-PCR assay was performed to assess the cecal tissue.

RESULTS: Adhesion formation was significantly reduced in PG0.25, 0.5, PL0.25, 0.5, and HA groups (2.5±0.7, 2.4±0.7, 3.8±1.0, 3.6±0.8, and 2.7±1.1, P<0.05). The incidence of abscesses was significantly reduced in all treated groups compared to RL group (58%, P<0.05). The urokinase-type plasminogen activator (uPA) gene expression was greatly up-regulated by increasing the concentration of polysaccharides. The urokinase-type plasminogen activator receptor (uPAR) and tumor necrosis factor (TNF)-α mRNA were highly expressed in PG0.25, 0.5, PL0.25, and 0.5 groups.

CONCLUSION: We concluded that 0.5% polysaccharide derived from PG and PL was the optimal concentration in preventing adhesion and abscess formation and may act by modulating activity of uPA and TNF-α in a rat peritonitis model.